Coupled thermo-hydro-mechanical simulation of CO2 enhanced gas recovery with an extended equation of state module for TOUGH2MP-FLAC3D

作     者：Yang Gou Zhengmeng Hou Mengting Li Wentao Feng Hejuan Liu 

作者机构：Energy Research Center of Lower SaxonyGoslarGermany Sino-German Energy Research CenterSichuan UniversityChengduChina Institute of Petroleum EngineeringClausthal University of TechnologyClausthal-ZellerfeldGermany Institut National de la Recherche Scientifique-Eau Terre Environnement Research Center(INRS-ETE)QuébecCanada 

出 版 物：《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报（英文版）)

年 卷 期：2016年第8卷第6期

页      面：904-920页

核心收录：

学科分类：0820[工学-石油与天然气工程] 083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 082002[工学-油气田开发工程] 

基　　金：funded by the National Natural Science Foundation of China(Grant No.NSFC51374147) the German Society for Petroleum and Coal Science and Technology(Grant No.DGMK680-4) 

主　　题：Carbon dioxide (CO2) enhanced gas recovery (CO2-EGR) CO2 sequestration Equation of state (EOS) Coupled thermo-hydro-mechanical (THM) modeling TOUGH2MP-FLAC3D 

摘      要：As one of the most important ways to reduce the greenhouse gas emission,carbon dioxide（CO2）enhanced gas recovery（CO2-EGR） is attractive since the gas recovery can be enhanced simultaneously with *** on the existing equation of state（EOS） module of TOUGH2 MP,extEOS7C is developed to calculate the phase partition of H2O-CO2-CH4-NaCl mixtures accurately with consideration of dissolved NaCI and brine properties at high pressure and temperature *** show that it can be applied up to the pressure of 100 MPa and temperature of 150℃.The module was implemented in the linked simulator TOUGH2MP-FLAC3 D for the coupled hydro-mechanical simulations.A simplified three-dimensional（3D）1/4 model（2.2 km×1 km×1 km） which consists of the whole reservoir,caprock and baserock was generated based on the geological conditions of a gas field in the North German *** simulation results show that,under an injection rate of 200,000 t/yr and production rate of 200,000 sm3/d,CO2breakthrough occurred in the case with the initial reservoir pressure of 5 MPa but did not occur in the case of 42 *** low pressure conditions,the pressure driven horizontal transport is the dominant process;while under high pressure conditions,the density driven vertical flow is *** the considered conditions,the CO2-EGR caused only small pressure *** largest pore pressure increase（2 MPa） and uplift（7 mm） occurred at the caprock bottom induced by only *** caprock had still the primary stress state and its integrity was not *** formation water salinity and temperature variations of ±20℃ had small influences on the CO2-EGR *** order to slow down the breakthrough,it is suggested that CO2-EGR should be carried out before the reservoir pressure drops below the critical pressure of CO2.